300 MORPHOLOGY AND EVOLUTION
Sealenus inedius (Seal. Med.) from C4. Omo-hyoid (0-H.M.) and sterno-thyroid
(S-T.M.) from 02; sterno-hyoid (S-H.M.)
from C2 and 03. Diaphragm by phrenic nerve (P.N.) from 02-
05. C. Cutaneous Branches (superficial).
Small occipital (O.N.), transverse cervical
(T.O.N.) from C2-C3. Acromial, clavicular and sternal from 03 and
04. Great auricular from 02.
FIG. 54.—The cervical plexus in the Chimpanzee. Letters explained
In the Gorilla the chief points in which the plexus
differs from the above are: (1) The loop between Cl
and 02 is double instead of single. (2) The supraclavi-
cular cutaneous- nerves are more numerous and form a
'plexus above the clavicle. (3) The sterno-mastoid
r muscle is innervated by 02 and 03. (4) The levator
anguli scapulae is innervated by 03 and 04, (5) The